1. Field of the Invention
This invention relates generally to wire drawing dies and methods of making such dies, and more particularly to a wire drawing die employing an irregular-shaped die element, and the method of making the same.
2. Description of the Prior Art
Wire drawing dies employing natural or man-made diamonds have been manufactured for many years, typically comprising a metal casing in which the diamond is mounted, the casing being adapted to be mounted in a wire drawing machine. U.S. Pat. No. 4,129,052 assigned to the assignee of the present application discloses a method of making a wire drawing die employing a synthetic hard, wear-resistant material such as a polycrystalline aggregate of synthetic diamond sold by the General Electric Company under the trademark Compax. In accordance with the method disclosed in that patent, a metal casing is provided having a flat-bottomed cavity machined therein, the side wall of the cavity adjacent the bottom being undercut. A first layer of metal powder is deposited in the casing covering the bottom and a metal blank having a core formed of synthetic hard, wear-resistant material is placed on the first layer with the core concentric with the cavity. A second layer of metal powder is deposited in the cavity covering the first layer and blank. A cylindrical plug is provided having a close fit with the casing cavity, one end of the plug having a cylindrical cavity formed therein. The plug is inserted in the casing cavity with the plug cavity facing the second metal powder layer, pressure is applied to the plug to compress the metal powder layer, and the casing and the plug are heated for a time and at a temperature sufficient partially to melt the metal powder thus forming a body of consolidated metal which encapsulates the blank. The casing is then cooled to solidify the metal body thereby to secure the blank and plug in the casing cavity. Countersunk openings are formed in the casing and the plug respectively extending to the core, and a die opening is drilled through the core communicating between the countersunk openings.
Some of the General Electric Compax die blanks have an irregular shape, such as the segment of a circle configuration shown in the aforesaid U.S. Pat. No. 4,129,052, and accurately centering such irregularly shaped die blanks in the casing cavity has been difficult and time consuming, and thus costly. It is therefore desirable to provide a method for quickly and precisely locating and mounting irregularly-shaped die elements, including synthetic hard, wear-resistant material and natural diamond, in the cavity of a die casing.